In the prior art, two types of linked metal or articulated rings such as finger rings are known. The first and probably oldest type is simply a form of chain or chain mail made small enough for the finger and is capable of flexing on all three axes, These rings are made by bending and soldering wire into various kinds of intersecting loops. The second type flexes on only two axes and in this respect resembles a common steel watch band or a caterpillar type tractor tread. For convenience, this type of construction will be referred to as an “articulated band”.
Articulated bands have been known at least since the beginning of the twentieth century and initially were made by a method of manufacture that required a skilled machinist with a hand lathe using links that were fabricated directly from tubular stock An alternate method involves the creation of model links via traditional jewelers techniques (carving of wax originals or filing of metal stock) then molding the resulting pieces in rubber for wax injection and casting using the lost wax process. In either case the pieces were joined together by drilling a hole through the link parts and soldering a wire or pin into place to hold the link segments together.
The “articulated bands” are still being made by the lathing method. The lathes are CNC (computer controlled) for greater efficiency and accuracy. Tubular precious metal stock is precision drilled for the pins. Then the CNC machine cuts out an entire set of links from the drilled metal tubular stock. The pins are then inserted and soldered together. Because the stock is drilled before the links are cut out, a precise alignment of the links is assured. This method has a drawback in that it results in the formation of gaps between the links which are sized according to the size of the milling machine tool head used to cut them apart. The prior art technique is illustrated in FIG. 4 where three links are aligned and drilled prior to the insertion of a pin. This procedure is repeated seriatim until the desired size is reached and the links are joined end to end to form the ring. Each link has the same dimensions which limits the ability to size the ring in conformance with standard ring sizing specifications. In addition, the drilling must be precisely controlled to provide for precise pin placement. Drill and pin techniques which could be utilized to achieve close tolerances between links have not been attempted due to prohibitive cost concerns. Even the current method of CNC production is far more expensive than our method because it produces great amounts of wasted materials e.g. precious metals such as gold, platinum and the like and requires skilled operators at the production level.
It has always been a problem to make an articulated band that exactly matches a common series of finger sizes. If a ring design is to have a fixed number of links; and the links are to be of the same size and of the same curvature for esthetic reasons, then each unique ring size requires a link model of the appropriate scale. There are at least ten common ring sizes and many more exceptional ones. This is not a problem with watch bands for instance because watch bands are provided with various kinds of adjustments. If rings are made using this technique, the cost of a separate model using a fixed articulated band design makes the availability of a collection of articulated band rings too expensive for mass manufacturing and distribution. The present invention combines CAD, stereolithography output models, a unique linking mechanism and conventional lost wax casting technology to make “articulated bands” that may be easily produced in multiple models and multiple ring sizes for a mass market. In addition, it allows a closer fit of the link units which produces esthetic improvements as well because the precise and closely spaced links provide an difference appearance as compared to widely spaced or irregularly spaced links.